Due to the geographic coverage nature of wireless service, there are hundreds of thousands of cell towers in the United States. For example, in 2014, it was estimated that there were more than 310,000 cell towers in the United States. Cell towers can have heights up to 1,500 feet or more. There are various requirements for cell site workers (also referred to as tower climbers or transmission tower workers) to climb cell towers to perform maintenance, audit, and repair work for cellular phone and other wireless communications companies. This is both a dangerous and costly endeavor. For example, between 2003 and 2011, 50 tower climbers died working on cell sites (see, e.g., www.pbs.org/wgbh/pages/frontline/social-issues/cell-tower-deaths/in-race-for-better-cell-service-men-who-climb-towers-pay-with-their-lives/). Also, OSHA estimates that working on cell sites is 10 times more dangerous than construction work, generally (see, e.g., www.propublica.org/article/cell-tower-work-fatalities-methodology). Furthermore, the tower climbs also can lead to service disruptions caused by accidents. Thus, there is a strong desire, from both a cost and safety perspective, to reduce the number of tower climbs.
As networks evolve, there is a continuous need to install equipment on cell towers, such as antennas, radios, and the like. Such equipment can weigh greater than 100 lbs, requiring construction equipment to raise it to the top of the cell tower or the like. Of course, the convention approach also requires tower climbs, is expensive, and inefficient. It would be advantageous to improve these approaches using UAVs, to reduce requirements for tower climbs, eliminate the need for construction equipment, lower cost, and improve installation time.
Existing cell sites and other sites typically include batteries for power backup in the event there is a disruption in commercial power service. This battery backup may support several hours or a day or so of power. However, once the battery backup is exhausted, the cell site can no longer operate until commercial power is restored. Due to weather or other natural disasters, there can be situations where commercial power is lost for longer than a few days and there is a desire to maintain power at these cell sites.